City Manager Jaime Fontes would not comment when asked why MacKinnon was placed on leave, saying it was a personnel matter, and as such he could not elaborate on what led to the action.

MacKinnon had applied for and been offered a job as a police chief in Arizona last month, but did not accept the job.

A native of Michigan, MacKinnon began working as the chief of the Santa Paula Police Department on Nov. 16, 2005. He succeeded Bob Gonzales, who retired in September 2005 after a 33-year career with the Santa Paula force.

Ish Cordero, a sergeant with Santa Paula Police Department and president of its Police Officers' Association, will serve as interim chief, Fontes said.

Cordero could not be reached for comment.

Gonzales, Santa Paula's mayor, said Fontes had informed him and other council members Tuesday morning of his decision to place MacKinnon on leave.

Gonzales said he and others on the council will wait for the investigation into MacKinnon to take its course. Fontes did not say how long he expects the investigation to take.

MacKinnon had applied for the job of chief of police in Clarkdale, a small town in central Arizona.

MacKinnon withdrew his candidacy after being offered the job in March, Gayle Mabery, town manager of Clarkdale, said Tuesday. MacKinnon did so for personal reasons, Mabery said.

MacKinnon could not be reached for comment Tuesday.

Gonzales said he had heard MacKinnon had applied for several jobs, including ones in California and Nevada.

MacKinnon was hired to lead the Santa Paula department after the city conducted a nationwide search for a new chief.

Before coming to Santa Paula, MacKinnon served as chief of police of three other agencies. He also served on the United Nations' International Policing Task Force in Haiti and Kosovo.

He began his career working as a patrol officer in Connecticut, where he was raised.

He later worked in Exeter and Salem, N.H., and in Avondale, Ariz.

He graduated from Northeastern University in Boston with a bachelor's degree in criminal justice. He also is a graduate of the FBI National Academy.